SrCo(1-x)FexO3的晶体结构和氧渗透性能

ＴＨＥＯＸＹＧＥＮＰＥＲＭＥＡＴＩＯＮＡＮＤＣＲＹＳＴＡＬＳＴＲＵＣＴＵＲＥＯＦＳｒＣｏ１－ｘＦｅｘＯ３＊ＬｉＳｉｗｅｎ，ＹａｎｇＷｅｉｓｈｅｎ＊＊，ＦａｎｇＬｉａｎｑｉｎｇ，ＬｉｎＬｉｗｕ（ＤａｌｉａｎＩｎｓｔｉｔｕｔｅｏｆＣｈｅｍｉｃａｌＰｈｙｓ...     

凝胶渗透色谱法测定甘蔗渣浆粕的分子量和分子量分布

本文介绍以丁酮为淋洗剂,用SN-OIA型G.P.C仪和Waters公司的聚苯乙烯标样(PS),得到标样和各试样的G.P.C谱图,并以一无线性回归法用TR-S-80微机处理数据,得到聚苯乙烯的校准曲线logM-V。(见方程)以相关系数接近I说明方程的可靠性;以丙酮为溶剂用水作沉淀剂分级甘蔗渣试样,然后按同理求出分级甘蔗渣浆粕的校准曲线logM—V.(见方程)和相关系数。根据方程和G.P.C谱图的各级分的高度,用微机直接打印出不同筛分浆粕的分子量及分子量分布。     

陶瓷—金属复合体系氢同位素渗透模型

在陶瓷（玻璃或氧化物）材料中氢同位素分子扩散的１次方定律和金属材料中原子扩散的１／２次方定律的基础上建立了双层介质扩散模型，推导出氢浓度分布函数，镀膜复合体的氢渗透速率以及渗透速率对驱动氢压的幂指数表达式，讨论了稳态氢渗透速率随膜厚，测量温度，驱动氢压变化的规律，根据实验测量的镀膜复合体的渗透速率，稳态渗透速率对驱动氢压依赖关系的幂指数大小，得以了膜材本身的渗透，扩散，溶解等热力学参数，同时估算了     

多孔媒质中液体的电声耦合

多孔媒质是充满连通管道的物质。在研究多孔媒质中液体的流动现象时发现，当流体相对于固－液界面处的带电表面运动时，由于液流和电磁场的耦合就出现了电声耦合（电动）现象。电动法同地震法结合，有可能成为油藏探测的潜在方法。     

煤的核磁共振成象研究

通过分别浸泡在氘代吡啶和氘代丙酮溶剂中的煤的核磁共振成象,观察了溶剂在煤中的渗透、扩散过程和溶胀作用。并得到了煤的大分子网络中的动态小分子的分布情况。由核磁共振成象技术获得了煤的化学和物理结构信息。     

温度对聚氧乙烯／共聚酯型聚氨酯共混物气体渗透行为影响的研究

在20°～80℃范围内的一系列温度下研究了H_2、N_2、O_2和CO_2气体对聚氧乙烯(PEO)/共聚酯型聚氨酯(PU)共混物的渗透行为。共混物透气系数的对数对温度的倒数作图符合Arrhenius关系,但在共混物中PEO熔点附近会出现转折点或突变;在PEO熔点上下,共混物有着完全不同的透气系数—组成曲线以及气体渗透活化能—组成曲线。结果说明了温度强烈影响共混物的气体渗透行为。     

纳米氧化锌对α-氧化铝管膜的改性研究

以硝酸锌和尿素为原料,采用均相沉淀法对一种法国商品α-氧化铝管膜进行改性。用SEM、FTIR、XRD等分析手段对改性前后的膜的结构性能进行了表征;测定了改性膜的渗透量及改性氧化铝粉体的电泳速率。结果表明:改性后在氧化铝膜层和氧化铝颗粒表面形成了一层均匀的纳米氧化锌涂层,其晶粒小于30纳米;改性后膜的流动电位及颗粒的电泳速率均有显著的降低,改性膜的渗透量提高156%。改性膜渗透量的显著提高被认为是由于膜的有效孔径增大和膜孔内壁附近过滤介质粘度降低所致。     

d-4-萜品醇丁酸酯的合成及其经皮促透活性评价

目的：合成新型化合物d-4-萜品醇丁酸脂（d-4-T-C4）,探究其对氟比洛芬（SR-FP）的促透作用并研究其促透机制。方法：以d-4-萜品醇（d-4-TER）、丁酸为原料,采用酰氯酯化法合成d-4-T-C4,并通过MS和1H-NMR进行结构表征。同时进行体外渗透实验,考察d-4-T-C4对SR-FP的体外促透活性,并利用红外光谱法和分子对接技术研究其促透机制。结果：加入d-4-T-C4时SR-FP的24 h累计透过量（Q24h）为383.5±48.75 ?g·cm-2,分别为对照组和d-4-TER组的3.12、1.34倍,均有显著差异（P<0.05）。同时通过对药物进行手性拆分可以发现d-4-T-C4对S-FP和R-FP的透过没有显著性差异（P>0.05）。通过探究促透机制发现d-4-T-C4插入角质层脂质结构域,破坏药物与神经酰胺之间的氢键相互作用,增加脂质迁移率和药物的自由能,从而促进药物的渗透。结论：d-4-T-C4对SR-FP具有显著的促透效果,有望作为新型促透剂在经皮给药系统中广泛应用。     

基于静电效应的石墨烯纳米孔选择性渗透特性

Two-dimensional graphene nanopores have proved to be a very effective molecular sieve with ultra-high molecular permeance due to the atomic thickness of graphene sheets. The mechanism of graphene nanopores for molecular sieving is generally the size-sieving effect of different molecules. However, high-selective molecular separation is difficult to realize based only on the size-sieving effect. Therefore, graphene nanopore-based membranes usually present high permeance but a moderate selectivity, such that the separation performance cannot far exceed those of traditional separation membranes. In this study, the effects of charges on graphene surfaces on the selective permeation of CO₂/N₂ mixtures through a graphene nanopore is studied using molecular dynamics simulations; its purpose to realize electrostatic effect-based selective molecular permeation through graphene nanopores and find a promising method to improve the selectivity of molecular separation. The simulation results show that graphene nanopores with negative charges have higher CO₂ permeance and lower N₂ permeance and, thus, present a high selectivity for the separation of the CO₂/N₂ mixtures. The graphene nanopore with positive charges, however, does not improve the selectivity. The electrostatic effect-based selectivity of graphene nanopores is related to the different molecular adsorption abilities on the graphene surface with charges. For negative charges, the adsorption ability of CO₂ molecules increases and the number of permeated molecules via surface mechanism increases and the experience time during the permeation process also increases; ultimately the CO₂ permeance increases with increasing the charge density. For the molecules permeated through the surface mechanism, they are firstly adsorbed onto the graphene surface and then diffuse to the pore region for the ultimate permeation; thus, their experience time is longer than that of the molecules permeated through a direct mechanism. Therefore, a longer experience time means a more significant contribution of the surface flux to the total flux. At high surface charge densities, the contribution of surface flux is dominated and thus the experience time is longer. For CO₂ molecules, the permeation rates increase with increasing the surface charge density. Namely, a higher experience time corresponds to a higher permeation rate for CO₂ molecules. A decrease of N₂ permeance with increasing the charge density is correlated to the increasing CO₂ permeance via the inhibition effects of non-permeating components on the permeation of permeating components. For positive charges, the adsorption abilities of CO₂ and N₂ molecules have no obvious variation with the charge density and their permeance is constant; therefore, the graphene nanopore still has no electrostatic effect-based selectivity.     

高等数学教学渗透研究性学习的研究与实践

近年来,研究性学习逐步成为高等教育教学改革的一个热点.在高等数学教学中实施研究性学习,可以有效改变学生多年来养成的应试性学习习惯,有利于培养学生的创新精神,提高学生的数学素养.做好研究性学习与传统教学的融合与协调,是高等数学教学中开展研究性学习的重要环节之一.我们在多年教学实践的基础上,形成了在传统教学模式中渗入研究性学习的课程教学理念,提出了研究性学习与传统教学融合与协调的教学新模式,并积极探索开展研究性学习的有效途径.教学实践表明,我们的做法既能发挥传统课堂教学的高效率,有助于改变学生的学习方式,提高其自主学习能力和创新能力